Machine-readable Map Feature list

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This page documents a proposed idea for one possible way of creating a Machine-readable Map Feature list (a structured formatted version of what we see on the Map Features wiki page) This proposal is for an XML formatted list generated using an approach which would require us to migrate this wiki to semantic mediawiki.

Existing implementations

Besides the proposal laid out on this page, there are in fact a number of existing implementations which are already up and running, offering data in XML or other formats.

Also note that all OSM wiki content is available in wiki dump files, updated daily

Aim

Generate a list of Map features that can be used in other programs. See the dev mailinglist

Use cases

Interactive Applications (editors, validators, etc.)

  • show a list of allowed tags for a given selection of OSM primitives (for instance in auto completion fields) -> example
  • show a list of allowed values for a given tag and given selection of OSM primitives (for instance in auto completion fields) -> example
  • warn users about key/value-pair for which there is no tag definition
  • warn users about redundant tags for a given selection of OSM primitives (if information about implied tags would be available in the list)
  • propose additional useful tag definitions in the context of a specific tag (example: user enters highway=residential and clicks in the context menü on "More tags ...". Applications proposes name=, access= and oneway= as additional tags)
  • display a structured list of tags, i.e. as tree or a menu, including icons, localized display names and descriptions
  • search in tag definitions, through keys, possible values and (localized) descriptions of tags (Example: user wants to tag a childrens playground. He is not sure whether the appropriate tag is amenity=playground, leisure=playground leisure=childrens_playground. He searches for 'childrens playground' and gets leisure=playground as a result)


Could be used in: JOSM, Potlatch

Others

Where can this list be useful?

  • Presets in JOSM/Merkator/Potlatch
  • Statistical usage in Tagwatch
  • Starting point for Mapnik/Osmarender/Kosmos rendering rules
  • Help files for used Tags (to explain the usage of existing Tags inside any editor)
  • Generation a clean Legend for the slippy map
  • easy multi-linguage support in editors without having to translate several times
  • Quick reference sheets
  • ... (add more)

File format

The file format is documented reusing the approach for the API v0.5.

Basic elements

localized descriptions and display names

display-name declares a localized display name of an object. description declares a localized description of an object. value-summary declares a localized summary of tag values

We use the xml:lang attribute to specifiy the language used.

<!ELEMENT description (#PCDATA)>
<!ATTLIST description  xml:lang  NMTOKEN #IMPLIED>

<!ELEMENT display-name (#PCDATA)>
<!ATTLIST display-name  xml:lang  NMTOKEN #IMPLIED>

<!ELEMENT value-summary (#PCDATA)>
<!ATTLIST value-summary xml:lang  NMTOKEN #IMPLIED>

map feature list (map-feature-list)

map-feature-list is the root element of the machine-readable map features list

It consists of tag-defs, categories and presets.


<!ELEMENT map-feature-list     ((tag-def|category|preset)*)>
<!ATTLIST map-feature-list  version      CDATA #REQUIRED>
<!ATTLIST map-feature-list  release-id   CDATA #REQUIRED>
<!ATTLIST map-feature-list  release-date CDATA #REQUIRED>
<!ATTLIST map-feature-list  xml:lang     NMTOKEN  "en">

tag definitions (tag-def)

tag-defs are definitions of tags. They are called tag definitions instead of tags because tag is reserved in API v0.5 for a specific key/value pair of an OSM primitive.

A tag-def defines

  • what key is used for this tag
  • to what kind of OSM primitives ( nodes, ways, relations, areas) a tag is applicable
  • the state in its life cycle (proposed, accepted, rejected, deprecated)
  • a set of localized display-names
  • a set of localized descriptions
  • a set of localized value-summaries
  • a set of references to categories this tag-def belongs to


A tag-def can declare a list of suggested, predefined values for the tag, which we call value definitions or value-defs.

<!ELEMENT tag-def              ((display-name|description|value-def|category|value-summary)*)>
<!ATTLIST tag-def key          CDATA #REQUIRED>
<!ATTLIST tag-def onnode       (yes|no)  "no">
<!ATTLIST tag-def onway        (yes|no)  "no">
<!ATTLIST tag-def onarea       (yes|no)  "no">
<!ATTLIST tag-def onrelation   (yes|no)  "no">
<!ATTLIST tag-def state        (draft|voting|proposed|accepted|rejected|deprecated) "accepted">

value definitions (value-def)

value-defs are suggested, predefined values for tags. Value definitions are also called labels.

A value-def defines

  • what key is used for this tag
  • to what kind of OSM primitives ( nodes, ways, relations, areas) the suggested value is applicable
  • a set of localized display-names
  • a set of localized descriptions
  • the state in its life cycle (proposed, accepted, rejected, deprecated)
<!ELEMENT value-def              ((display-name|description)*)>
<!ATTLIST value-def value         CDATA #REQUIRED>
<!ATTLIST value-def onnode       (yes | no)  "no">
<!ATTLIST value-def onway        (yes | no)  "no">
<!ATTLIST value-def onarea       (yes | no)  "no">
<!ATTLIST value-def onrelation   (yes | no)  "no">
<!ATTLIST value-def state        (draft|voting|proposed|accepted|rejected|deprecated)  "accepted">

categories (category)

A category groups a set of tag definitions.

A category defines

  • a unique name
  • an (optional) icon name for the category (16x16)
  • a set of localized display-names
  • a set of localized descriptions
<!ELEMENT category              ((display-name|description)*)>
<!ATTLIST category  name        ID #IMPLIED>
<!ATTLIST category  ref         IDREF #IMPLIED>
<!ATTLIST category  icon        CDATA "">

cat-ref is used to link a tag-def to a category.

   <!-- refers to a category with name physiscal defined elsewhere in the file -->
   <category ref="physical">

preset

A preset is a partially defined set of tags (key/value-pairs). Interactive applications use presets to tag certain map objects with consistent set of tags. presets are transient. In contrast not nodes, ways and relations they are not stored in the OSM database. They are supposed to assist users in applying "correct" tags for specific real-world objects.

presets are therefore mainly useful for interactive applications (aka editors). To offline data validation tools information about used presets is not available.


A preset can

  • imply that a specific key/value-pair be used. Interactive applications can automatically add implied key/value-pair to the tag set of an OSM primitive.
  • require that an arbitrary value for a specific key be used. Interactive applications must prompt users to select a value for required keys.
  • suggest that an arbitrary value for a specific key be used. Interactive applications may prompt users to select a value for a suggested key.

A preset defines

  • a unique name
  • a set of localized display-names
  • a set of localized descriptions
<!ELEMENT implies                EMPTY>
<!ATTLIST implies   key          CDATA #REQUIRED>
<!ATTLIST implies   value        CDATA #REQUIRED>

<!ELEMENT requires                EMPTY>
<!ATTLIST requires   key          CDATA #REQUIRED>
 
<!ELEMENT suggests                EMPTY>
<!ATTLIST suggests   key           CDATA #REQUIRED>

<!ELEMENT preset   ((implies|requires|suggests|display-name|description)*)>
<!ATTLIST preset   name          NMTOKEN #REQUIRED>

Full DTD

The current version of the DTD is available from the SVN repository.

<!ELEMENT map-feature-list     ((tag-def|category|preset)*)>
<!ATTLIST map-feature-list  version      CDATA #REQUIRED>
<!ATTLIST map-feature-list  release-id   CDATA #REQUIRED>
<!ATTLIST map-feature-list  release-date CDATA #REQUIRED>
<!ATTLIST map-feature-list  xml:lang     NMTOKEN  "en">

<!ELEMENT description (#PCDATA)>
<!ATTLIST description  xml:lang  NMTOKEN #IMPLIED>

<!ELEMENT display-name (#PCDATA)>
<!ATTLIST display-name  xml:lang  NMTOKEN #IMPLIED>

<!ELEMENT value-summary (#PCDATA)>
<!ATTLIST value-summary xml:lang  NMTOKEN #IMPLIED>


<!ELEMENT tag-def              ((display-name|description|value-def|category|value-summary)*)>
<!ATTLIST tag-def key          CDATA #REQUIRED>
<!ATTLIST tag-def onnode       (yes|no)  "no">
<!ATTLIST tag-def onway        (yes|no)  "no">
<!ATTLIST tag-def onarea       (yes|no)  "no">
<!ATTLIST tag-def onrelation   (yes|no)  "no">
<!ATTLIST tag-def state        (draft|voting|proposed|accepted|rejected|deprecated)  "accepted">


<!ELEMENT value-def              ((display-name|description)*)>
<!ATTLIST value-def value         CDATA #REQUIRED>
<!ATTLIST value-def onnode       (yes | no)  "no">
<!ATTLIST value-def onway        (yes | no)  "no">
<!ATTLIST value-def onarea       (yes | no)  "no">
<!ATTLIST value-def onrelation   (yes | no)  "no">
<!ATTLIST value-def state        (draft|voting|proposed|accepted|rejected|deprecated)  "accepted">


<!ELEMENT category              ((display-name|description)*)>
<!ATTLIST category  name        ID #IMPLIED>
<!ATTLIST category  ref         IDREF #IMPLIED>


<!ELEMENT implies                EMPTY>
<!ATTLIST implies   key          CDATA #REQUIRED>
<!ATTLIST implies   value        CDATA #REQUIRED>

<!ELEMENT requires                EMPTY>
<!ATTLIST requires   key          CDATA #REQUIRED>
 
<!ELEMENT suggests                EMPTY>
<!ATTLIST suggests   key           CDATA #REQUIRED>

<!ELEMENT preset   ((implies|requires|suggests|display-name|description)*)>
<!ATTLIST preset   name          NMTOKEN #REQUIRED>

Examples

Example 1 - 3 tag definitions, 3 categories, not localized, no images, no presets

  • not localized, i.e. assumes xml:lang = "en"
  • tag-def operator is assigend to category naming and to category non-physical
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE osm-tag-def-list SYSTEM "osm-tag-definition-list.dtd" >

<osm-tag-def-list release-date="2008-12-20" release-id="00001" version="0.1">


<tag-def key="highway" onnode="yes" onway="yes" onarea="yes">
	<display-name>Highway</display-name>
	<description>The highway tag is the primary tag used for highways. It is often the only tag. There are conventions for its use in particular countries.</description>
	
	<value-def value="motorway" onway="yes">
		<display-name>Motorway</display-name>
		<description>A restricted access major divided highway, normally with 2 or more running lanes plus emergency hard shoulder. Equivalent to the Freeway, Autobahn, etc.. </description>		
	</value-def>

	<value-def value="motorway_link" onway="yes">
		<display-name>Motorway Link</display-name>
		<description>The link roads (sliproads/ramps) leading to/from a motorway from/to a motorway or lower class highway. Normally with the same motorway restrictions. </description>		
	</value-def>

	<value-def value="pedestrian" onway="yes" onarea="yes">
		<display-name>Pedestrian</display-name>
		<description>For roads used mainly/exclusively for pedestrians/shopping areas. Also for tagging squares and plazas (in which case, add area=yes.</description>		
	</value-def>

	<value-def value="bus_stop" onnode="yes">
		<display-name>Bus Stop</display-name>
		<description>A small bus stop. Larger stations should be tagged as amenity=bus_station instead. </description>		
	</value-def>
	<category ref="physical" />
</tag-def>


<tag-def key="operator" onnode="yes" onway="yes" onarea="yes">
	<display-name>Operator</display-name>
	<description>The operator tag can be used to name a company or corporation who's responsible for a certain object or who operates it.</description>		

	<category ref="naming"/>
	<category ref="non-physical"/>
</tag-def>


<tag-def key="name" onnode="yes" onway="yes" onarea="yes">
	<display-name>Name</display-name>
	<description>The common default name. (Note: For disputed areas, please use the name as displayed on e.g. street signs for the name tag. Put all alternatives into either localized name tags (e.g. name:tr/name:el) or the variants (e.g. loc_name/old_name/alt_name). Thank you.) </description>		
	
	<category ref="naming"/>
</tag-def>


<category name="physical">
	<display-name>Physical</display-name>	
</category>

<category name="non-physical">
	<display-name>Non-Physical</display-name>	
</category>

<category name="naming">
	<display-name>Naming</display-name>	
</category>



</osm-tag-def-list>

Maintaining map features on the OSM wiki

Tags have to be defined on the Wiki in a way that they

  • can automatically be converted to a Wiki page for users
  • can easily be harvested by a robot in order to generate the machine-readable Map feature list

Where tag definitions are maintained today

Today, tag definitions are maintained in several places on the Wiki:

Examples: Key:highway
Template:KeyDescription declares a subset of the data we need for tag-def. Shortcomings:
  • no data about a localized display name
  • no data about whether the key is applicable to a relation
  • can refer to one group (we call them category) only
  • no data about the status in the life cycle
Examples: Tag:highway=motorway
Template:ValueDescription declares a subset of the data we need for value-def. Shortcomings:
  • no data about a localized display name
  • no data about whether the key is applicable to a relation
  • template pages for each tag definition which collect the value definitions for a specific tag definition (but only for accepted features), i.e. Template:Map_Features:highway. They usually include a wiki table with a predefined structure. Shortcomings:
  • the main Map Features page for accepted features which mainly includes the individual templates pages for each accepted key
  • the main page for Proposed_features. In contract to Map Features this page doesn't assemble sub pages. It uses a couple of templates to declare proposed features, in particular


Using Semantic MediaWiki in the future

An upgrade of the OSM wiki to the Semantic MediaWiki (SMW) could help to reduce redundant definitions of tags and values, see talk mailing list. The idea has been discussed extensively on the discussion page. The discussion led to a propsoal for a new structure of the OSM wiki regarding pages, which include content about map features.

Basic concepts

See subarticle OWL, Semantic MediaWiki and more

Classes

We have four classes (in OWL terminology). Naming conventions follow those used in OWL, i.e.:

  • camel case for class names, first letter upper case
  • camel case for property name, first letter lower case

Some of the properties have multiplicity 1, others 0..1 and other *. It is not possible to restrict multiplicity in SMW. It seems that multiplicity is always *: just repeat a property declaration with another value in order to assign multiple values to it. For clarity, the intended multiplicity of the properties is given below in [..].


KeyDef

An individual of KeyDef describes a key used in OSM for tagging a map element.
Semantic Properties:
Name Multiplicity Type Description
key 1 (mandatory) String the defined key, i.e. highway or access
displayName * String an localized display name for the key. Should not include HTML or wiki formatting because it will be used by applications other than the OSM wiki. See below on how localized display names for multiple languages are maintained.
description * String an localized description for the key. Should not include HTML or wiki formatting because it will be used by applications other than the OSM wiki. See below on how localized description for multiple languages are maintained.
onNode 0..1 (optional) Boolean whether this key is applicable to nodes or not. If missing, false is assumed.
onWay 0..1 (optional) Boolean whether this key is applicable to ways or not. If missing, false is assumed.
onArea 0..1 (optional) Boolean whether this key is applicable to areas or not. If missing, false is assumed.
onRelation 0..1 (optional) Boolean whether this key is applicable to relations or not. If missing, false is assumed.
state 0..1 (optional) String either draft, voting, proposed, accepted,rejected, or deprecated; if missing, accepted is assumed.
lang 1 (mandatory) String the language of language dependent properties like displayName or description.
photo 0..1 (optional) Page the value of photo refers to an image with a photo of a typical real-world situation where an OSM map feature can be used.
rendering 0..1 (optional) Page The value of rendering refers to a sample rendering of a map feature on a map
group * Page holds the name of a group this KeyDef belongs to.
implies * Page refers to another map feature which is implied by this KeyDef. Example values are Key:highway (referring to another KeyDef) or Tag:highway/primary (referring to another ValueDef)
requires * Page refers to another map feature which is required by this KeyDef. Example values are Key:name (referring to another KeyDef) or Tag:access/no (referring to another ValueDef)
suggests * Page refers to another map feature which is suggested to be used together with this KeyDef. Example values are Key:name (referring to another KeyDef) or Tag:access/no (referring to another ValueDef)

ValueDef

An individual of ValueDef is a Name/Value-Pair used in OSM for tagging a map element.
Semantic Properties:
Name Multiplicity Type Description
key 1 (mandatory) String the defined key, i.e. highway or access
key 1 (mandatory) String the defined value, i.e. primary or yes
displayName * String an localized display name for the key. Should not include HTML or wiki formatting because it will be used by applications other than the OSM wiki. See below on how localized display names for multiple languages are maintained.
description * String an localized description for the key. Should not include HTML or wiki formatting because it will be used by applications other than the OSM wiki. See below on how localized description for multiple languages are maintained.
onNode 0..1 (optional) Boolean whether this key is applicable to nodes or not. If missing, false is assumed.
onWay 0..1 (optional) Boolean whether this key is applicable to ways or not. If missing, false is assumed.
onArea 0..1 (optional) Boolean whether this key is applicable to areas or not. If missing, false is assumed.
onRelation 0..1 (optional) Boolean whether this key is applicable to relations or not. If missing, false is assumed.
state 0..1 (optional) String either draft, voting, proposed, accepted,rejected, or deprecated; if missing, accepted is assumed.
lang 1 (mandatory) String the language of language dependent properties like displayName or description.
photo 0..1 (optional) Page the value of photo refers to an image with a photo of a typical real-world situation where an OSM map feature can be used.
rendering 0..1 (optional) Page The value of rendering refers to a sample rendering of a map feature on a map
group * Page holds the name of a group this ValueDef belongs to.
implies * Page refers to another map feature which is implied by this KeyDef. Example values are Key:highway (referring to another KeyDef) or Tag:highway/primary (referring to another ValueDef)
requires * Page refers to another map feature which is required by this KeyDef. Example values are Key:name (referring to another KeyDef) or Tag:access/no (referring to another ValueDef)
suggests * Page refers to another map feature which is suggested to be used together with this KeyDef. Example values are Key:name (referring to another KeyDef) or Tag:access/no (referring to another ValueDef)

Preset

An individual of Preset describes, how an OSM element is tagged with various map features in order to precisely describe a kind of real-world objects.
Semantic Properties:
Name Multiplicity Type Description
name 1 (mandatory) String the unique name of the preset, i.e. hotel
displayName * String an localized display name for the preset. Should not include HTML or wiki formatting because it will be used by applications other than the OSM wiki. See below on how localized display names for multiple languages are maintained.
description * String an localized description for the preset. Should not include HTML or wiki formatting because it will be used by applications other than the OSM wiki. See below on how localized description for multiple languages are maintained.
lang 1 (mandatory) String the language of language dependent properties like displayName or description.
implies * Page refers to another map feature which is implied by this Preset. Example values are Key:highway (referring to another KeyDef) or Tag:highway/primary (referring to another ValueDef)
requires * Page refers to another map feature which is required by this Preset. Example values are Key:name (referring to another KeyDef) or Tag:access/no (referring to another ValueDef)
suggests * Page refers to another map feature which is suggested to be used together with this KeyDef. Example values are Key:name (referring to another KeyDef) or Tag:access/no (referring to another ValueDef)

Group

An individual of Group describes a specific group of map features.
Semantic Properties:
Name Multiplicity Type Description
name 1 (mandatory) String the unique name of the group primary
displayName * String an localized display name for the group. Should not include HTML or wiki formatting because it will be used by applications other than the OSM wiki. See below on how localized display names for multiple languages are maintained.
description * String an localized description for the group. Should not include HTML or wiki formatting because it will be used by applications other than the OSM wiki. See below on how localized description for multiple languages are maintained.
lang 1 (mandatory) String the language of language dependent properties like displayName or description.

Relationship between classes and Wiki categories

For each class we create a wiki category, i.e.

  • Category:KeyDef
  • Category:ValueDef
  • Category:Group
  • Category:Preset

Relationships between properties and Wiki pages

In SWW, we can describe each property in a respective page in the namespace Property:, for instance Property:name or Property:implies. Creating property pages is not mandatory, but it makes sense, because the page provides semantic information about the property to editors. Editors can learn there what the meaning of a specific property is and what range of values are acceptable for this property.

Following the OSM philosophy, editors are still free to use whatever property they want, assigning whatever value they feel appropriate. However, editors are strongly encouraged to use a canonical set of semantic properties (those defined in the preceding sections) consistently.

A property page includes

  • a declaration of its type using [[Has Type::aType]], i.e. [[Has Type::String]]
  • standard wiki text which describes the properties to editors

It does not include, however:

  • a formal declaration of the properties multiplicitiy. Multiplicity must be described to users in the wiki text

Individuals and how we maintain them on the SMW

A specific key (for instance highway)

  • create a page Key:highway
  • include property declarations in the wiki source. They set the instantiated properties (OWL lingo), i.e. the property values for this individual. You may use a trailing | in [[property::value | ]] if setting the property should be invisible. Here's an example:
 [[key::highway]]
 [[onNode::false]]
 [[onArea::true]]
 [[onWay::true]]
 [[onRelation::false]]
 [[state::accepted]]
 [[group::physical]]
Alternatively, you may want to use {{#set: key=highway}} which silently sets the property key
  • make sure it is marked as individual of the class KeyDef by including the following wiki category
 [[Category:KeyDef]]
  • make sure there is at least one language specific page with language specific properties, for instance En:Key:highway. It should include
 [[displayName::Highway]]
 [[description::This is the description for Highway]]
 [[lang::en]]
Furthermore, this page will include the rest of the wiki text for this key in english.

A specific value (for instance highway/residential)

  • create a page Tag:highway/residential
  • include property declarations in the wiki text. They define the instantiated properties (OWL lingo), i.e. the property values for this individual. You may use a trailing | in [[property::value | ]] if setting the property should be invisible. Here's an example:
 [[key::highway]]
 [[value::residential]]
 [[onNode::false]]
 [[onArea::false]]
 [[onRelation::false]]
 [[state::accepted]]
 [[group::physical]]
Alternatively, you may want to use {{#set: key=highway}} which silently sets the property key
  • make sure it is marked as individual of the class ValueDef by including the following wiki category in the text
  [[Category:ValueDef]]
  • make sure there is at least one language specific page with language specific properties, for instance En:Tag:highway/residential. It should include
 [[displayName::Residential road]]
 [[description::This is the description for a residential road ]]
 [[lang::en]]
Furthermore, this page will include the rest of the wiki text for this value in english.

A specific group (for instance physical)

  • create a page Group:physical
  • include property declarations in the wiki text. They set the instantiated properties (OWL lingo), i.e. the property values for this individual. You may use a trailing | in [[property::value | ]] if setting the property should be invisible. Here's an example:
 [[name::physical]]
Alternatively, you may want to use {{#set: name=physical}} which silently sets the property name
  • make sure it is marked as individual of the class Group by including the following wiki category
  [[Category:Group]]
  • make sure there is at least one language specific page with language specific properties, for instance En:Group:physical. It should include
 [[displayName::Physical]]
 [[description::Description for feature category Physical]]
 [[lang::en]]
Furthermore, this page will include the rest of the wiki text for this group.

A specific preset (for instance residential_road)

  • create a page Preset:residential_road
  • include property declarations in the wiki text
 [[name::residential_road]]
 [[requires::Tag:highway/residential]]
 [[suggest::Key:name]]
 [[suggest::Tag:oneway/yes]]
 [[suggest::Key:maxspeed]]
Alternatively, you may want to use {{#set: name=residential}} which silently sets the property name


  • make sure it is marked as individual of the class Preset
  [[Category:Preset]]
  • make sure there is at least one language specific page with language specific properties, for instance En:Preset:residential_road. It should include
 [[displayName::Residential Road]]
 [[description::Description Residential Road ]]
 [[lang::en]]
Furthermore, this page will include the rest of the wiki text for this Preset.

Proposal for structuring map feature pages

Currently, map feature pages are maintained in specific pseudo-namespaces for map feature pages:

  • the pseudo-namespace Key: is reserved for key definitions
  • the pseudo-namespace Tag: is reserved for tag definitions (what we call ValueDef above)

We continue with this approach in SWM:

  • the pseudo-namespace Key: will be reserved for key definitions. Example page title: Key:highway
  • the pseudo-namespace Tag: will be reserved for value definitions. Example page title: Tag:highway/residential
  • the pseudo-namespace Group: will be reserved for group definitions. Example page title: Group:physiscal
  • the pseudo-namespace Preset: will be reserved for group definitions. Example page title: Preset:redisentialRoad

For technical reasons we have to avoid equal signs (=) in page titles. SMW can't cope with them in semantic queries. Current page titles like Tag:highway=primary therefore have to be changed to Tag:highway/primary.

Internationalization / Localization

Most of the semantic properties of KeyDef, ValueDef, Group and Preset are languge independet. For instance, neither key nor value nor onNode has to be localized. There are, however, some semantic properties, whose values have to translated in several languages, for instance

  • displayName
  • description

Map feature pages are therefore maintained in one or more "language flavors" (as we always did on the OSM wiki):

  • For each map feature there will be a default article, say Key:highway for a key definition or Tag:highyway/primary for a tag definition, which respresents the individual and declares its language and country independent semantic properties. This article includes the language dependent semantic properties and the language dependent wiki text in english.
  • For each map feature there will be additional language specific page, for instance DE:Key:highway or DE:Tag:highway/primary, which describe the map feature to human readers and declare language specific semantic properties. Here semantic content and human readable content is mixed. Optionally there are other language specific articles for the same map feature, i.e. FR:Tag:highway/primary. There is, however, no language namespace EN:. English is the default language.

Furthermore some semantic properties have country specific values:

  • There can be a country specific, language independent articles, for instance Tag:highway/primary/UK which includes the declarations of country specific semantic properties in english.
  • There can be a country specific, language dependent articles, for instanceDE:Tag:highway/primary/UK which includes the description of country specific properties in a specific language to humans. It also declares language and country specific semantic information.

Object properties and internationalized page titles

In the preceding section we introduced internationalized and localized page titles for map feature pages

  • using a languag prefix for languages (TR:Key:highway)
  • using a country postfix for countries (DE:Key:highway/CH)

In the context of SWN, property values are always considered to be wiki links. A property declaration [[description::This is a long description]] will lead to a wiki link This is a long description.

Some of our properties in SWN are, in OWL lingo, object properties, i.e. their instantiated object properties refer to other individuals. If we refer to other individuals of KeyDef, ValueDef, Group or Preset we newer include a language prefix or a country postfix in the value.

Valid examples:

  • [[implies::Key:highway]]
  • [[suggests::Tag:highway/primary]]

Invalid examples:

  • [[implies::EN:Key:highway]]
  • [[group::DE:Tag:highway/primary/CH]]

Object properties therefore refer to the page in the default language. If we want to direct readers to a specific language dependent page, then we have to hide the property declaration and to add a wiki link explicitly, i.e.

 [[implies::Key:highway | ]] <!-- hide the property declaration -->  
 Implies [[FR:Key:highway |<tt>highway</tt>]] <!-- add an explicit link to the french page --> 

Harvesting map features

Data flow and tool chain (aka "architecture")

See also

Infrastructure

Archive

Outdated stuff, less useful stuff